The present invention relates to a syringe. More specifically, the present invention relates to a syringe that generates audible clicks as the plunger rod moves relative to the barrel.
Syringes with mechanisms for regulating or monitoring movement of a plunger along a barrel are known. For instance:                U.S. Pat. No. 3,934,586 to Easton describes a syringe with tabs on the plunger rod that engage with wedges extending radially inwards from the barrel;        DE807,113 describes a syringe with tabs extending from the plunger rod and a regulator attachable to the outer perimeter of the barrel to regulate relative movement of the plunger rod and barrel; and        U.S. Pat. No. 4,642,102 to Ohmori describes a stopper secured to and incrementally movable along the plunger rod, which stopper limits relative movement of the plunger rod and barrel when the stopper comes into contact with the barrel.        
It is an object of the present invention to provide an insert for a syringe that is separate from the barrel, that is sized to locate within the barrel, and that creates an audible sound when the plunger rod moves relative to the barrel.